Addiction vulnerability genes include those that are likely to harbor allelic variants that contribute to human individual differences in vulnerability to addictions. During this year, we identified more than 80 such genes based on the covergences between nominally-positive data derived from four separate abuser/control comparisons, and appeared to add to evidence supporting roles for many of these genes with additional data from a comparison between nicotine depdendent and control samples. Genes identified in this fashion include a disproportionate number of genes whose products are involved in "cell adhesion" molecule actions. During this year we identified the frequent functional variations at the loci that contain these genes, including splicing variants, missense variants, veriations in 3' and 5' untranslated regions, variations in 5' flanking sequences and variaitons in natural antisense tanscripts. A number of these variations appear to be closely associaiated with addiction vulnerability haplotypes. During the year we reported resutls from studies of other addiction vulnerability genes, including NrCAM, BDNF and the cannabanoid CB1 and CB2 receptor genes.